In a letter sent this week to “transportation stakeholders,” including the Lancaster County Commissioners, state transportation Secretary Leslie Richards said PennDOT has approved the research group’s application to test the vehicles, and that testing may occur in 25 counties, including Lancaster.

The move greatly expands the presence of automated testing in Pennsylvania. Previously, testing was permitted only in Allegheny, Bucks, Chester, Delaware and Philadelphia counties, according to a list on PennDOT’s website as of Nov. 9.

James Cowhey, executive director of the county planning commission, said he expects local officials to receive further notification before any actual testing begins.

Heads up Lancaster County drivers! Penndot has notified us Automated Vehicle testing may occur here. So that 🚗 you are following could be a robot. More details here ⬇️ pic.twitter.com/I2XQmhBIT0

Some Lancaster County residents balked at the news that state transportation officials wanted Pennsylvania to be a testing ground, according to a January 2017 LNP report.

One concern was how the cars would navigate horse and buggy traffic. At that time a PennDOT spokeswoman said autonomous vehicles can detect slow-moving objects on the road and shoulder such as buggies.